Your First Fish: Happy, Healthy Goldfish Require Diligent Care

"Can we get some goldfish, Mommy?" my 5-year-old daughter asked me during a recent discussion about pets. "Maybe," I said. "But Mommy needs to do some research first." Boy, did I.

Goldfish are a great choice for a pet, but they still require more care than many first-time goldfish owners might think, says Dr. Greg Lewbart, MS, VMD, Dipl. ACZM, professor of Aquatic Animal Medicine at North Carolina State University’s College of Veterinary Medicine. Dr. Lewbart has specialized in aquatic medicine for 25 years, and, he says, 50 to 75 percent of the cases he treats are regular goldfish or their larger family members, koi.

If you think you can plop a goldfish into a tiny little bowl with some rocks at the bottom and call it a day, you're mistaken. Here's what goldfish owners need to know to keep their pretty little pets happy and healthy.

Forget the Fishbowl

Small fishbowls aren’t good homes for goldfish, says Dr. Lewbart. “A 29-gallon tank is best, and no smaller than 20 gallons,” he says, because goldfish need wiggle room. And the more volume of water in the tank, the longer it takes for the water to become polluted by fish waste, excess food, algae or bacteria — and therefore, the healthier your fish will be.

Also, Dr. Lewbart recommends putting a hood or top over the tank because goldfish like to jump. “Bad things happen to good fish,” Dr. Lewbart says. “They find a way to get into trouble.”

Goldfish are temperate fishes, says Dr. Lewbart, and not native to the United States. They’re used to temperature fluctuation, but are most comfortable around 70 degrees.

Make a Happy-Fish Shopping List

There are many sizes and types of supplies for tanks. Dr. Lewbart recommends starting with the basics for a beginner’s system.

Power filter — A good power filter will help keep your tank clean.

Substrate — Some sort of gravel at the bottom of the tank makes it look nice.

Net — A very fine mesh net works best to scoop your fish and nudge them around the tank as needed during cleaning. But don’t overhandle your fish, Dr. Lewbart cautions.

Thermometer — Knowing the current temperature of the water, so that, if needed, you can make adjustments is critical in keeping your fish healthy and happy.

Heater back up — While your goldfish tank doesn’t need a heater, if you lose heat in your home for some reason, a backup heater can keep the water from getting too cold.

Dechlorinating agent — Most municipal water will have a bit of chlorine in it, Dr. Lewbart says, so make sure you treat the water with a dechlorinating agent when you first set up the tank and each time you add new water.

Aquarium salt — Goldfish like a little salt in their water, says Dr. Lewbart. It helps with transition and stress and can even help keep some health issues at bay. Read instructions on the package to avoid oversalting.